The present invention provides a method for automatically shifting computer resources from a standby system to an active system by using a prediction technique.
In recent years, outsourcing with the object of reducing the necessary expense is proceeding in purchase, supply and maintenance of service, software and infrastructures. Computer use of “on demand” type has been proposed. In the computer use of “on demand” type, necessary computer resources are used when needed, and a charge is paid according to the amount used. Outsourcing to computer centers having a large quantity of computer resources represented by conventional computer centers such as data centers and utility centers is proceeding. It is considered that this movement will be further accelerated by application of the grid computing technique to the business field. Here, the maintenance of idle computer resources and a resultant cost pose a problem. In the conventional computer operation, computer resources are introduced in expectation of specifications at the time of maximum operation needed instantaneously. Usually, therefore, a large number of idle computer resources are present. Maintaining the computer resources constitutes a barrier to the cost reduction. In a method disclosed in JP-A-9-81409, a computer has an active system and a standby system. A standby system processing function that can be automatically associated when a fault has occurred is selected and associated. A hot standby relation is constructed, and the standby system becomes an active system for another computer. Since the standby system can become an active system for another computer in this method, it becomes possible to implement reduction of standby system resources and reduction of idle computer resources. In a method disclosed in JP-11-328129, only resources shared by all jobs are connected and it is made possible to cope with any execution system job. As a result, the number of standby system jobs in the system is reduced, and it is attempted to use resources efficiently as regards computers and memories and reduce the system operation load and cost.
In the conventional techniques, other services are not operated on the same server. Therefore, the total number of servers cannot be decreased in the form of, for example, server integration. The same holds true for computer resources other than servers. In the case where the load varies depending upon the time zone, it is necessary to prepare enough computer resources to withstand a high load and it is difficult to reduce computer resources. In addition, since the standby system becomes a computer resource group always having the same setting as that of the active system in the conventional technique, it is necessary to maintain a standby system every service and it is difficult to reduce the computer resources. Furthermore, since overload in computer resources of the active system is predicted in the conventional technique on the basis of the current load value, precision of resource scheduling is low. In that respect as well, it is difficult to form a configuration in which surplus resources are mutually lent among a plurality of services.